php regex select less code - php

Question

I want to select all less code from a file .But i can not find the right way to do it.
This is my code so far
$d = <<<EOT
.class {
width:100%;
height:100%;
background-image: url(images/fallback-gradient.png);
}
.id {
b:100%;
bc: url(images/fallback-gradient.png);
}
& when ( #main_container_top_option = true) {
.fast_menu_option {
.gpicon {
color: transparent;
}
}
}
EOT;
$pattern = '/.*\{(?s:.*?)\}$/mi';
$t = preg_match_all($pattern, $d, $out, PREG_PATTERN_ORDER);
foreach ($out[0] as $key) {
echo '<br><pre>'.$key."</pre>";
}
And this is the result:
.class {
width:100%;
height:100%;
background-image: url(images/fallback-gradient.png);
}
.id {
b:100%;
bc: url(images/fallback-gradient.png);
}
& when ( #main_container_top_option = true) {
.fast_menu_option {
.gpicon {
color: transparent;
}
For the first 2 classes is ok but last one is not ok because they are missing 2 other }.
How can i fix it?

Answer 1

It looks like you want to match individual blocks, so a recursive pattern will return balanced braces. As stated in comments under the question, this method may break when character anomalies occur. I believe there are css parsers out "in the wild" but I don't have any to recommend.
Code: (Demo)
if (preg_match_all('~.*\{((?R)|[^}])*}~', $d, $out)) {
echo implode("\n---\n",$out[0]);
}
Output:
.class {
width:100%;
height:100%;
background-image: url(images/fallback-gradient.png);
}
---
.id {
b:100%;
bc: url(images/fallback-gradient.png);
}
---
& when ( #main_container_top_option = true) {
.fast_menu_option {
.gpicon {
color: transparent;
}
}
}
If you don't need to separate the blocks, you can modify the pattern like this:
~[^{]*\{((?R)|[^}])*}~
But then it depends on what your actual input.